alex chen
2017-Oct-24 12:46 UTC
[Ocfs2-devel] [PATCH v3] ocfs2: the ip_alloc_sem should be taken in ocfs2_get_block()
The ip_alloc_sem should be taken in ocfs2_get_block() when reading file
in DIRECT mode to prevent concurrent access to extent tree with
ocfs2_dio_end_io_write(), which may cause BUGON in the following situation:
read file 'A' end_io of writing file
'A'
vfs_read
__vfs_read
ocfs2_file_read_iter
generic_file_read_iter
ocfs2_direct_IO
__blockdev_direct_IO
do_blockdev_direct_IO
do_direct_IO
get_more_blocks
ocfs2_get_block
ocfs2_extent_map_get_blocks
ocfs2_get_clusters
ocfs2_get_clusters_nocache()
ocfs2_search_extent_list
return the index of record which
contains the v_cluster, that is
v_cluster > rec[i]->e_cpos.
ocfs2_dio_end_io
ocfs2_dio_end_io_write
down_write(&oi->ip_alloc_sem);
ocfs2_mark_extent_written
ocfs2_change_extent_flag
ocfs2_split_extent
...
--> modify the
rec[i]->e_cpos, resulting
in v_cluster <
rec[i]->e_cpos.
BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos))
Fixes: c15471f79506 ("ocfs2: fix sparse file & data ordering issue in
direct io")
Signed-off-by: Alex Chen <alex.chen at huawei.com>
Reviewed-by: Jun Piao <piaojun at huawei.com>
Acked-by: Changwei Ge <ge.changwei at h3c.com>
---
fs/ocfs2/aops.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 88a31e9..d151632 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -134,6 +134,19 @@ static int ocfs2_symlink_get_block(struct inode *inode,
sector_t iblock,
return err;
}
+static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int ret = 0;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+
+ down_read(&oi->ip_alloc_sem);
+ ret = ocfs2_get_block(inode, iblock, bh_result, create);
+ up_read(&oi->ip_alloc_sem);
+
+ return ret;
+}
+
int ocfs2_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
@@ -2128,7 +2141,7 @@ static void ocfs2_dio_free_write_ctx(struct inode *inode,
* called like this: dio->get_blocks(dio->inode, fs_startblk,
* fs_count, map_bh, dio->rw == WRITE);
*/
-static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock,
+static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
@@ -2154,12 +2167,9 @@ static int ocfs2_dio_get_block(struct inode *inode,
sector_t iblock,
* while file size will be changed.
*/
if (pos + total_len <= i_size_read(inode)) {
- down_read(&oi->ip_alloc_sem);
- /* This is the fast path for re-write. */
- ret = ocfs2_get_block(inode, iblock, bh_result, create);
-
- up_read(&oi->ip_alloc_sem);
+ /* This is the fast path for re-write. */
+ ret = ocfs2_lock_get_block(inode, iblock, bh_result, create);
if (buffer_mapped(bh_result) &&
!buffer_new(bh_result) &&
ret == 0)
@@ -2424,9 +2434,9 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct
iov_iter *iter)
return 0;
if (iov_iter_rw(iter) == READ)
- get_block = ocfs2_get_block;
+ get_block = ocfs2_lock_get_block;
else
- get_block = ocfs2_dio_get_block;
+ get_block = ocfs2_dio_wr_get_block;
return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
iter, get_block,
--
1.9.5.msysgit.1
Joseph Qi
2017-Oct-25 01:15 UTC
[Ocfs2-devel] [PATCH v3] ocfs2: the ip_alloc_sem should be taken in ocfs2_get_block()
On 17/10/24 20:46, alex chen wrote:> The ip_alloc_sem should be taken in ocfs2_get_block() when reading file > in DIRECT mode to prevent concurrent access to extent tree with > ocfs2_dio_end_io_write(), which may cause BUGON in the following situation: > > read file 'A' end_io of writing file 'A' > vfs_read > __vfs_read > ocfs2_file_read_iter > generic_file_read_iter > ocfs2_direct_IO > __blockdev_direct_IO > do_blockdev_direct_IO > do_direct_IO > get_more_blocks > ocfs2_get_block > ocfs2_extent_map_get_blocks > ocfs2_get_clusters > ocfs2_get_clusters_nocache() > ocfs2_search_extent_list > return the index of record which > contains the v_cluster, that is > v_cluster > rec[i]->e_cpos. > ocfs2_dio_end_io > ocfs2_dio_end_io_write > down_write(&oi->ip_alloc_sem); > ocfs2_mark_extent_written > ocfs2_change_extent_flag > ocfs2_split_extent > ... > --> modify the rec[i]->e_cpos, resulting > in v_cluster < rec[i]->e_cpos. > BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos)) > > Fixes: c15471f79506 ("ocfs2: fix sparse file & data ordering issue in direct io") > > Signed-off-by: Alex Chen <alex.chen at huawei.com> > Reviewed-by: Jun Piao <piaojun at huawei.com> > Acked-by: Changwei Ge <ge.changwei at h3c.com>>I don't think we have to rename ocfs2_dio_get_block. Anyway it doesn't matter. Reviewed-by: Joseph Qi <jiangqi903 at gmail.com>> --- > fs/ocfs2/aops.c | 26 ++++++++++++++++++-------- > 1 file changed, 18 insertions(+), 8 deletions(-) > > diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c > index 88a31e9..d151632 100644 > --- a/fs/ocfs2/aops.c > +++ b/fs/ocfs2/aops.c > @@ -134,6 +134,19 @@ static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock, > return err; > } > > +static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock, > + struct buffer_head *bh_result, int create) > +{ > + int ret = 0; > + struct ocfs2_inode_info *oi = OCFS2_I(inode); > + > + down_read(&oi->ip_alloc_sem); > + ret = ocfs2_get_block(inode, iblock, bh_result, create); > + up_read(&oi->ip_alloc_sem); > + > + return ret; > +} > + > int ocfs2_get_block(struct inode *inode, sector_t iblock, > struct buffer_head *bh_result, int create) > { > @@ -2128,7 +2141,7 @@ static void ocfs2_dio_free_write_ctx(struct inode *inode, > * called like this: dio->get_blocks(dio->inode, fs_startblk, > * fs_count, map_bh, dio->rw == WRITE); > */ > -static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock, > +static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock, > struct buffer_head *bh_result, int create) > { > struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); > @@ -2154,12 +2167,9 @@ static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock, > * while file size will be changed. > */ > if (pos + total_len <= i_size_read(inode)) { > - down_read(&oi->ip_alloc_sem); > - /* This is the fast path for re-write. */ > - ret = ocfs2_get_block(inode, iblock, bh_result, create); > - > - up_read(&oi->ip_alloc_sem); > > + /* This is the fast path for re-write. */ > + ret = ocfs2_lock_get_block(inode, iblock, bh_result, create); > if (buffer_mapped(bh_result) && > !buffer_new(bh_result) && > ret == 0) > @@ -2424,9 +2434,9 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > return 0; > > if (iov_iter_rw(iter) == READ) > - get_block = ocfs2_get_block; > + get_block = ocfs2_lock_get_block; > else > - get_block = ocfs2_dio_get_block; > + get_block = ocfs2_dio_wr_get_block; > > return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, > iter, get_block, >
Gang He
2017-Oct-25 02:05 UTC
[Ocfs2-devel] [PATCH v3] ocfs2: the ip_alloc_sem should be taken in ocfs2_get_block()
>>> > The ip_alloc_sem should be taken in ocfs2_get_block() when reading file > in DIRECT mode to prevent concurrent access to extent tree with > ocfs2_dio_end_io_write(), which may cause BUGON in the following situation: > > read file 'A' end_io of writing file 'A' > vfs_read > __vfs_read > ocfs2_file_read_iter > generic_file_read_iter > ocfs2_direct_IO > __blockdev_direct_IO > do_blockdev_direct_IO > do_direct_IO > get_more_blocks > ocfs2_get_block > ocfs2_extent_map_get_blocks > ocfs2_get_clusters > ocfs2_get_clusters_nocache() > ocfs2_search_extent_list > return the index of record which > contains the v_cluster, that is > v_cluster > rec[i]->e_cpos. > ocfs2_dio_end_io > ocfs2_dio_end_io_write > > down_write(&oi->ip_alloc_sem); > ocfs2_mark_extent_written > ocfs2_change_extent_flag > ocfs2_split_extent > ... > --> modify the rec[i]->e_cpos, > resulting > in v_cluster < > rec[i]->e_cpos. > BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos)) > > Fixes: c15471f79506 ("ocfs2: fix sparse file & data ordering issue in direct > io") > > Signed-off-by: Alex Chen <alex.chen at huawei.com> > Reviewed-by: Jun Piao <piaojun at huawei.com> > Acked-by: Changwei Ge <ge.changwei at h3c.com>Reviewed-by: Gang He <ghe at suse.com>> > --- > fs/ocfs2/aops.c | 26 ++++++++++++++++++-------- > 1 file changed, 18 insertions(+), 8 deletions(-) > > diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c > index 88a31e9..d151632 100644 > --- a/fs/ocfs2/aops.c > +++ b/fs/ocfs2/aops.c > @@ -134,6 +134,19 @@ static int ocfs2_symlink_get_block(struct inode *inode, > sector_t iblock, > return err; > } > > +static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock, > + struct buffer_head *bh_result, int create) > +{ > + int ret = 0; > + struct ocfs2_inode_info *oi = OCFS2_I(inode); > + > + down_read(&oi->ip_alloc_sem); > + ret = ocfs2_get_block(inode, iblock, bh_result, create); > + up_read(&oi->ip_alloc_sem); > + > + return ret; > +} > + > int ocfs2_get_block(struct inode *inode, sector_t iblock, > struct buffer_head *bh_result, int create) > { > @@ -2128,7 +2141,7 @@ static void ocfs2_dio_free_write_ctx(struct inode > *inode, > * called like this: dio->get_blocks(dio->inode, fs_startblk, > * fs_count, map_bh, dio->rw == WRITE); > */ > -static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock, > +static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock, > struct buffer_head *bh_result, int create) > { > struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); > @@ -2154,12 +2167,9 @@ static int ocfs2_dio_get_block(struct inode *inode, > sector_t iblock, > * while file size will be changed. > */ > if (pos + total_len <= i_size_read(inode)) { > - down_read(&oi->ip_alloc_sem); > - /* This is the fast path for re-write. */ > - ret = ocfs2_get_block(inode, iblock, bh_result, create); > - > - up_read(&oi->ip_alloc_sem); > > + /* This is the fast path for re-write. */ > + ret = ocfs2_lock_get_block(inode, iblock, bh_result, create); > if (buffer_mapped(bh_result) && > !buffer_new(bh_result) && > ret == 0) > @@ -2424,9 +2434,9 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, > struct iov_iter *iter) > return 0; > > if (iov_iter_rw(iter) == READ) > - get_block = ocfs2_get_block; > + get_block = ocfs2_lock_get_block; > else > - get_block = ocfs2_dio_get_block; > + get_block = ocfs2_dio_wr_get_block; > > return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, > iter, get_block, > -- > 1.9.5.msysgit.1